Networks are used to join computing systems at different sites and across the world. Networks may also be used to couple components of a single system. In a datacenter, a computing system may include several internal networks to carry communications between the various components. Even though the components may be physically separated in different enclosures, the networks enable the components to act as one.
Networks, whether internal or external, may take any of a number of different forms and topologies. For example, some networks use a star topology where each entity (a discrete system, a component, etc.), is coupled to a central access point such as a router or switch. As an alternative, some networks use a ring topology, where, as the name implies, each entity is coupled to two other entities to form a single loop or ring. Packets may be forwarded along the ring from entity to entity until the destination is reached, and the ring network may be unidirectional or bidirectional, allowing packets to be forwarded in a single direction or both directions, respectively.